With the increased availability of parallel computer resources amenable to large scale scientific computing, it is essential to optimize the use of these resources. These optimization efforts include the development of parallel computing techniques suitable for macromolecular simulation, and the development of a parallel workstation cluster and related software for high-efficiency simulations at low cost. Development of methods and software to make productive use of parallel MIMD machines for use in macromolecular simulations is underway. The initial global communication approach has been successful in providing an efficient full feature version of CHARMM. This parallel version of CHARMM has been extended to run on almost any MIMD parallel computer platform. Our current development effort involves a scalable algorithm that promises to greatly reduce the communication cost for very large MPP machines or for large workstation clusters. Current projects include: a.Workstation Clusters Environment Development and support of CHARMM Efficient utilization of a high speed workstation cluster of HP735s Development of parallel QM/MM methods b. Large Scale Parallel Computers Development and support of parallel CHARMM Development of a 10 teraflop GRAPE computer (RIKEN) for macromolecular simulation Development and evaluation of scalable parallel algorithms for molecular dynamics Development of an efficient communication scheme for a ring-topology computer (Terra) c. Other Ongoing Development Efforts Development of efficient Macintosh software for macromolecular modeling Development of ray-traced molecular graphics software for HP workstations, high resolution color printers, and for movies using NTSC video equipment Development of video editing and titling software for molecular movies